Certain converters for powering electric motors are conventional. In this context, an intermediate circuit voltage provided for powering an inverter is mostly generated from an a.c. network voltage, using a rectifier. During regenerative operation, the energy generated is consumed by a braking resistor, which is supplied current by a brake chopper, i.e., an electronic circuit breaker. The heat generated at the braking resistor must be dissipated, for which appropriate space is provided, in particular for air flow, as well. In addition, a converter is necessary for each electric motor.